BORON. RAMSAY. 151 



In the last column I have added my own calculation of 

 the atomic weight directly from the analytical ratio a found 

 (from Na Cl). 



Since, by standard atomic weights, the anhydrous borax 

 is 1584-4 Bo and sodium chloride is 117, and the analytical 

 ratio is the latter divided by the former, it follows that 

 4 Bo = q 158 where q nz 1 17 : a. 



From this expression our atomic weight given above is 

 calculated. 



We notice that all our values are very near n and oscil- 

 late to both sides of this number; the mean is only 8 thou- 

 sandths less than n. 



The comparison of this last column with the first under 

 Na Cl shows strikingly that the constant error has disap- 

 peared by taking our standard values for the auxiliary atomic 

 weights, namely, Na = 23, and Cl = 35.5, instead of the 

 Clarke values Na = 23.05 and Cl = 35.45, used by Ramsay. 



This gives an additional demonstration that the com- 

 monly used auxiliary values are false, and to what an extent 

 their small errors will affect the final value of good chemical 

 determinations. Compare page 33. 



It is, of course, thoroughly understood that we merely 

 wished to show the effect of taking our standard values also 

 in this form of the direct calculation of the atomic weight. 



We are, however, only interested in the one true absolute 

 value of the atomic weight of boron, which is eleven 

 exactly, as we have proved. 



Determinations by Henry Gautier. 



In the chemical laboratory of Professor Moissan, of the 

 University of Paris, Henry Gautier has recently made four 

 series of determinations of the atomic weight of boron. 



The results have been presented by Moissan himself to 

 the Academy of Sciences of Paris, and are printed in the 

 Comptes Rendus, T. 129, pp. 595-598 and 678-681 for 1899. 



A more complete record of this work is published on pp. 

 352-382 of Tome 18, of the Annales de Chimie et de Phy- 

 sique, Paris, 1899 (direction includes Moissan). 



At the annual public session of the Academy, on Decem- 

 ber 17, 1900, the Vaillant prize was awarded to Henry 

 Gautier for this investigation on the recommendation of the 



